Who iscredited with the first accurate model of your dna

James Watson is the first who elaborate DNA model ( double helix) .He corporate with Francis Crick

The name of the instrument that the scientist uses is called a microscope.a microscope is used to view objects which is not visible to the naked eyes

By water evaporation from the leaves is created a negative pressure at the top of the tree that promotes the ascension  of the water through channels that are called xylem. there are also two molecule forces that are involved: the intra-water molecules cohesion (water molecules stick to each other) and the adhesion when the water molecules stick to the channels they are running in. this is what enables water to go from the roots to the top of a tall tree.